PubMed Health⌕ Search

Biomedical subjects

Edelgard Lindhoff-Last

Publications and source records attributed to Edelgard Lindhoff-Last.

17 recordsLinked to original sources

Response to aspirin and clopidogrel monitored with different platelet function methods.

Laboratory non-response to aspirin or clopidogrel is defined as an inability to cause in vitro detectable platelet function inhibition. It would be beneficial to monitor response to aspirin or clopidogrel with widely available and routinely used platelet function methods, like the platelet function analyzer (PFA-100) or the fully automated coagulation analyzer BCT. The aim of this study was to assess the potential of the coagulation analyzer BCT and the platelet function analyzer PFA-100 in monitoring the response of aspirin and clopidogrel. A group of 125 consecutive patients with arterial occlusive disease treated either with aspirin 100 mg/day (82 patients) or clopidogrel 75 mg/day (43 patients) as only antiplatelet drug were investigated. For the first time platelet-enriched plasma (PRP), not adjusted to a fixed predetermined concentration of platelets, was used for aggregation studies and the effect of clopidogrel alone without combination of aspirin treatment on platelet function was investigated. Response to aspirin was observed in 85% (70/82) of patients using PFA-100, while performing the arachidonic acid-induced aggregation on the BCT showed an inhibitory effect to aspirin in 91% (75/82) of patients. Non-response to aspirin was assessed with both platelet function methods in 7% (6/82) of patients. Clopidogrel response was observed in 58% (25/43) of patients when performing ADP-induced aggregation on the BCT. On the PFA-100 the antiplatelet effect of clopidogrel could not be detected. In conclusion, measurement of platelet aggregation on the BCT using native platelet-enriched plasma allows the quantification of individual inhibitory effects to aspirin as well as to clopidogrel, while the PFA-100 seems only suitable to investigate the degree of platelet inhibition induced by aspirin but not by clopidogrel.

Aged↗

Detection of heterozygous large deletions in the antithrombin gene using multiplex polymerase chain reaction and denatured high performance liquid chromatography.

The present study reports a method for the easy, rapid and cost effective detection of heterozygous large deletions. As a model gene all exons of the antithrombin gene were amplified in a one tube multiplex polymerase chain reaction (PCR) and the products separated according to their size by reverse-phase ion-pair high performance liquid chromatography. A significant reduction in the height of a peak in the probandOs sample compared to in the control indicates the presence of a large deletion of the corresponding allele. Using this approach we identified heterozygous deletions in four patients: the deletions affected exons 1 and 2, exon 7 and the whole antithrombin gene.

Antithrombin III↗

Management of cutaneous type IV hypersensitivity reactions induced by heparin.

Localized hypersensitivity reactions to subcutaneous heparin injections have been described since 1952. Yet, the incidence of these reactions, which are distinct from skin lesions associated with heparin-induced thrombocytopenia type II (HIT II), remains uncertain. However, in the last 10 years an increasing number of patients have been reported, leading to the assumption that cutaneous hypersensitivity reactions towards heparin are underreported. Clinically patients present with itching, sometimes infiltrated, and blistering erythemas at the injection sites of heparins. The diagnosis of cutaneous heparin allergy may, on the one hand, lead to delay of required medical or surgical treatment. On the other hand, delayed initiation of treatment may lead to a generalized eczematous reaction. Hence, from review of 223 cases of patients with cutaneous hypersensitivity reactions to heparin, we here summarize the clinical picture of cutaneous type IV allergic reactions, define risk factors on both the patient- and drug-side, and give an overview of principle therapeutic alternatives, as well as recommendations for treatment options for emergency and elective patients. As the proposed management of patients with cutaneous hypersensitivity reactions to heparin may have fatal consequences when applied in patients with HIT type II, diagnosis of skin lesions in heparin-treated patients needs to be precise.

Drug Hypersensitivity↗

Percutaneous laser-assisted recanalization of long chronic iliac artery occlusions: primary and mid-term results.

We report the primary and mid-term outcome of patients with long chronic iliac artery occlusions after percutaneous excimer-laser-assisted interventional recanalization. Between 2000 and 2001, 43 patients with 46 chronic occlusions of either the common iliac artery (n=27), the external iliac artery ( n=13) or both (n=3) underwent laser-assisted percutaneous transluminal angioplasty and implantation of stents. The average length of the occlusion was 57.1+/-26 mm. After laser-assisted angioplasty and implantation of a total of 60 stents, the patients were followed up for up to 4 years. Patency rates were analyzed by ankle-brachial index (ABI) measurement and duplex ultrasound. The primary technical success rate was 95.3%, with a major complication rate of 6.9%. Clinical improvement as categorized by the Rutherford guidelines could be observed in 97.6% of cases. The ABI of all patients improved from an average of 0.46+/-0.08 before intervention to 0.97+/-0.13 at the end of the follow-up period. The overall primary patency rate was 86.1%. Four reinterventions were successful (secondary patency rate 95.4%). The mid-term results of the percutaneous recanalization of iliac artery occlusions with primary and secondary patency rates of 86.1 and 95.4% are similar to those of the treatment of short stenoses.

Adult↗

Platelet activation markers in patients with venous thromboembolism without predisposing factors.

A constant in vitro hypersensitivity of platelets (adenosine diphosphate) has been suggested as a risk factor for arterial and even venous thrombosis. Our aim was to determine phenotypic and functional alterations of platelets by flow cytometry as potential prothrombotic risk factors in patients with a history of unexplained spontaneous venous thrombosis. Forty-nine patients with a history of spontaneous venous thrombosis and no inherited or acquired thrombophilic risk factors were compared with a reference group of 39 healthy volunteers. Flow cytometry (FACS) was used to analyze the surface expression of CD62 (P-selectin) and CD63 in nonactivated platelets and after in vitro stimulation with adenosine diphosphate and thrombin receptor activator peptide 6. Mean fluorescence intensity of CD62 and CD63 surface expression as well as percentage of CD62 and CD63 positive cells and binding index differed in patients with a history of thrombosis compared with the reference group, but failed to reach statistical significance. Similar results were observed after in vitrostimulation with adenosine diphosphate and thrombin receptor activator peptide 6. In conclusion, the expression of CD62 and CD63 of resting and in vitro activated platelets could not be established as a risk factor for spontaneous venous thromboembolism.

Adenosine Diphosphate↗

Treatment of 51 pregnancies with danaparoid because of heparin intolerance.

Pregnant patients with acute venous thrombosis or a history of thrombosis may need alternative anticoagulation, when heparin intolerance occurs. Only limited data on the use of the heparinoid danaparoid are available in literature. We reviewed the use of danaparoid in 51 pregnancies of 49 patients identified in literature between 1981 and 2004. All patients had developed heparin intolerance (32 due to heparin-induced thrombocytopenia, 19 mainly due to heparin-induced skin rashes) and had a current and/or past history of thromboembolic complications. The initial danaparoid dose regimens ranged from 1000 to 7500 U/day administered s.c. or i.v.. The median duration of danaparoid use was 10 weeks. Danaparoid was used until delivery of a healthy infant in 37 pregnancies. In the remaining 14 pregnancies it was stopped earlier, because anticoagulant treatment was no longer required (3/14) or an adverse event led to a treatment discontinuation (11/14). Four maternal bleeding events were recorded during pregnancy, delivery or postpartum, two of them were fatal due to placental problems. Three fetal deaths were recorded, all associated with maternal complications antedating danaparoid use. Danaparoid cross-reactivity was suspected in 4 HIT patients and 5 non-HIT patients with skin reactions and was confirmed serologically in one of the two HIT patients tested. In none of five fetal cord blood- and three maternal breast milksamples anti-Xa activity transfer was observed. In conclusion danaparoid can be used as an alternative antithrombotic agent in pregnant women with high thrombotic risk and intolerance to heparins.

Adult↗

Molecular weight determines the frequency of delayed type hypersensitivity reactions to heparin and synthetic oligosaccharides.

Eczematous lesions, resulting from type IV sensitizations are well-known and relatively frequent cutaneous adverse effects of s.c. heparin therapy. If anticoagulation is further required intravenous heparin, heparinoids or lepirudin may be used as a substitute. However, these alternatives are not optimal in terms of practicability and/or safety-profiles. As molecular weight of different heparin preparations has repetitively been implied to determine the frequency of sensitization, we hypothesized, that due to its low molecular weight the pentasaccharide fondaparinux may provide a practicable and safe anticoagulant therapy in patients with delayed type hypersensitivity reactions (DTH) to heparin and other oligosaccharides. To test this concept, patients referred for diagnosis of cutaneous reactions after s.c. anticoagulant treatment underwent a series of in vivo skin allergy- and challenge-tests with unfractionated heparin, a series of low molecular weight heparins (nadroparin, dalteparin, tinzaparin, enoxaparin and certoparin), the heparinoid danaparoid and the synthetic pentasaccharide fondaparinux. In total, data from twelve patients was evaluated. In accordance with previously published data, we report a high crossreactivity among heparins and heparinoids. In contrast--and in support of our initial hypothesis--sensitization towards the synthetic pentasaccharide fondaparinux was rarely observed. Plotting the cumulative incidence against the determined molecular weight of the individual anticoagulant preparations, shows that molecular weight generally is a key determinant of sensitization towards heparins and other oligosaccharides (r2 = 0.842, p = 0.009). Hence, fondaparinux may be used as a therapeutic alternative in patients with cutaneous DTH relations towards heparin and other polysaccharides.

Adult↗

Acquired protein C and protein S deficiency in HIV-infected patients.

Infection with human immunodeficiency virus (HIV) may lead to hemostatic imbalances. Forty-nine consecutive patients with acute opportunistic infections were screened for thrombophilic parameters. A follow-up investigation was performed after 10 +/- 8 weeks in 26 patients. In acutely ill patients, the incidence of protein S deficiency was 67% (33/49) and of protein C deficiency 25% (12/49), while at the follow-up visit the incidences were 54% (14/26) and 8% (2/26), respectively. Protein S and protein C levels increased significantly from initial to follow-up visit (p < 0.05). Lupus anticoagulants were not detected and anticardiolipin IgG antibodies were present in 11.4% (5/44). Three patients presented with deep venous thrombosis on admission; in two, protein S or protein C deficiency was observed. In conclusion, an acquired protein S and protein C deficiency often develop in patients with HIV and acute illness; this may be reversible after treatment for opportunistic infections.

Adolescent↗

Incidence and clinical relevance of heparin-induced antibodies in patients with deep vein thrombosis treated with unfractionated or low-molecular-weight heparin.

The frequency of heparin-induced thrombocytopenia (HIT) varies between different clinical treatment settings and remains unknown for patients treated with unfractionated (UFH) or low-molecular-weight heparin (LMWH) because of deep vein thrombosis. In this multicentre, open-label study, 1137 patients with deep vein thrombosis were randomly assigned to UFH for 5-7 d, reviparin, a LMWH, for 5-7 d (short-treated group) or reviparin for 28 d (long-treated group). Heparin-platelet factor 4 antibodies (HPF4-A) were determined on d 5-7 and d 21. Heparin-induced thrombocytopenia was defined by clinical evaluation. Two patients in the UFH group (incidence: 0.53%, 95% confidence interval (CI): 0.06-1.91) and two patients in the long-treated LMWH group (incidence: 0.53%, 95% CI: 0.06-1.92) had HIT, while no HIT was observed in the short-treated LMWH group. Pulmonary embolism developed in one of the HIT-patients, who had HPF4-A and was treated with UFH. On d 5-7 the incidence of HPF4-A was 9.1% in the UFH group, 2.8% in the short-treated LMWH group and 3.7% in the long-treated LMWH group, with a significant increase to 20.7% in the UFH group and to 7.5% in the long-treated LMWH group on d 21. Therefore the incidence of HPF4-A and heparin-induced thrombocytopenia was lower in patients treated with LMWH compared with UFH for the same duration of treatment.

Anticoagulants↗

Heparin-induced thrombocytopenia-alternative anticoagulation in pregnancy and lactation.

Heparin-induced thrombocytopenia (HIT) appears rarely in pregnant patients who are being treated with heparin. When HIT is suspected, heparin treatment should be discontinued and alternative anticoagulation should be started. The heparinoid danaparoid appears to be the drug of choice for acute treatment and prophylaxis because of its low placental permeability. Between the 12th and 36th weeks of pregnancy, either danaparoid may be continued or warfarin may be used after recovery of platelet counts. Before and during delivery, danaparoid should be preferred over warfarin in order to avoid bleeding complications in mother and infant. Hirudin should only be used when either cross-reactivity with heparin-induced antibodies or cutaneous allergy against heparinoids are observed. Postpartum warfarin seems to be the treatment of choice because breast-feeding can be continued. Alternative treatment with either danaparoid or hirudin is possible, but data on treatment with these reagents in lactating mothers are very limited.

Adult↗

MIXCON-LA: a precise, sensitive and specific aPTT-based assay for detection of lupus anticoagulant.

Lupus anticoagulants (LA) are associated with an increased risk of thrombosis and laboratory detection is of major importance. Multiple tests are available for screening and confirmation, but they differ in sensitivity and specificity, frequently lacking the ability to discriminate between the presence of LA, heparin, and oral anticoagulants. Based on the test-principle of the Lupus Ratio-test, an automated, sensitive APTT-based assay, using mixtures of a lupussensitive and a lupusinsensitive APTT-reagent with normal plasma for detection of lupus anticoagulants was developed. Ninety-nine healthy volunteers, ten patients treated with unfractionated heparin intravenously, 19 patients taking stable oral anticoagulation, five patients with hemophilia A, and 15 patients with antiphospholipid-antibody-syndrome (APS) were investigated. In all patients, two APTTs were performed, one with each reagent, on 1:1 mixtures of test plasma and normal plasma (MIXCON-LA assay). The ratio between the two clotting times was divided by the corresponding ratio for the normal plasma. This final lupus ratio (LR) was used for evaluation. The within-series imprecision and the between-series imprecision were excellent with coefficients of variation between 1.5% and 1.9%. The mean +/- 2 SD of the LR of the 99 healthy volunteers was used as reference range (LR: 0.95-1.07). All patients treated either with heparin or oral anticoagulants remained negative in the MLXCON-LA assay (specificity, 100%), while one of five patients with hemophilia A, in whom a factor VIII-inhibitor developed, showed a false-positive result. In 13 of 15 patients with APS, an increased ratio was observed (sensitivity, 87%). This assay system allows precise, specific, and sensitive detection of lupus anticoagulants.

Adult↗

Risk factors and long-term follow-up of patients with the immune type of heparin-induced thrombocytopenia.

Dispositional risk factors for developing the immune-type of heparin-induced thrombocytopenia (HIT) are yet unclear. This article presents a long-term follow-up of patients with HIT to define possible risk factors that may increase the risk of HIT. The clinical course of acute HIT was analyzed retrospectively in 52 patients with HIT. Thirteen patients died; 8 due to HIT. A follow-up investigation was performed in 28 of the remaining 39 patients 29 +/- 12 months after the onset of HIT, including genotyping for the factor V G1691A- and the prothrombin G20210A-mutation, measurement of antithrombin, protein C, protein S, factor VIII, and factor XII activity as well as the concentration of antiphospholipid antibodies. The results were compared to an age- and sex-matched control group. New thromboembolic events and re-exposure to heparin were also documented. No difference between patients and controls was observed concerning the factor V Leiden mutation, the prothrombin mutation, factor XII, antithrombin, protein S, or protein C deficiency and antiphospholipid antibodies. Increased factor VIII activity was found in 16 of 21 HIT patients compared to 4 of 21 controls (p=0.0005). New thromboembolic events developed in 5 patients within 9 months after HIT. One patient had been re-exposed to heparin 9 months after acute HIT without any complications. Increased factor VIII activity was frequently observed in patients in whom HIT developed. Thromboembolic complications within the first months after onset of HIT occurred often.

Aged↗